Gotham City's citizens (Jason Todd, Holly and Harley) are returning home and trying to adjust to life after traversing the multiverse. Jason decides that he's finished going the "crazy" route but is determined to continue in the war against crime. Elsewhere in the city, Pied Piper, thought to have been destroyed along with Apokolips (Countdown #9) finds himself safe and sound in the gutters of Gotham. He picks himself up off the street and decides that he will use his new lease on life to join the fight on the "side of the angels."

Ray Palmer is also adjusting to life while sitting alone in his house. He isn't alone for much longer however when Donna Troy, Kyle Rayner, Jimmy Olsen and Forager arrive at his doorstep. All feeling listless and unfulfilled after their journeys, they find themselves wondering - who exactly monitors the Monitors? As if on cue, Nix Uotan (the monitor of the twice destroyed Earth-51) arrives and bands the Challengers together once more as a civilian troupe with the purpose of keeping an eye on the now individualized Monitors. The purpose of this group is  to make sure none go rogue as Solomon did.

Deep in the middle of the desert, Mary Marvel finds Black Adam. He refutes her request to join him and as she explodes in a tantrum he calls her a child and simply flies away. Mary Marvel, once a warrior for the side of good finds herself alone and full of hatred for society.

Back in the hollowed out wreckage of Bludhaven, Buddy Blank and his grandson are left inside of Command-D (after Brother Eye left and headed towards Apokolips in Countdown #15). Brother Eye, having survived the destruction of Apokolips, arrives back on Earth and transforms Buddy into a new prototype of OMAC (one similar to the original OMAC from back in the day). Now that Buddy has been granted the super powers of OMAC while retaining his free will, he is able to take himself and his grandson out of the bunker and out of Bludhaven.

The Challengers arrive at the Multiversal Nexus and put the other monitors on notice. Ray Palmer, Donna, Kyle, and Forager will serve as "border guards" and will keep the flawed Monitors in line. Ray Palmer goes so far as to renounce his Earth and state that his true home is in the multiverse himself - along with his fellow anomalies. Solomon, lurking in the shadows smiles and begins planning for this new "game."

Like all of the challengers, Harley Quinn finds herself at home in Gotham, worried at her inability to control or even predict the vastness of it all. Her new roommate Holly steps out onto the fire escape with her. While staring up at their Earth's moon she too wonders, just how will they move on from here? Harley best sums it up - "A Positive attitude and lots of denial?"

Holly just smiles at her new friend and tells her never to change.

NOTE:
Although the "Countdown" title has ended, story continues in DC Universe #0